Gardens

Japanese Maples: The Aristocrats of Ornamental Trees
Planted in the right place in a well-drained, nutrient rich soil, Japanese maples are an easy to grow jewel of a tree.

by Sid Mullis

The Japanese maple is an interesting and aristocratic tree that is sure to enhance any yard or garden. It goes back well over 1,000 years with Japanese gardeners not only growing maples as specimen trees, but also cultivating them in large pots as garden features or in small containers as bonsai. These enchanting trees have likewise charmed modern gardeners with their brilliant crimson foliage in the spring, followed by bright green leaves of summer, then red, orange or gold leaves in the fall.

Edgefield County gardener J.L. Fountain is one such fan. “Some people like to hunt and fish as their hobby. Mine is playing in the yard and the plant I like most is the Japanese maple. I have 45 of them in my landscape,” he says.

Fascination with Japanese maples is easy to understand: They are exquisitely beautiful trees. Probably the only reason you don’t see more of them is their cost.  A red Japanese maple in a three-gallon container can cost in excess of $100. A seedling might sell for $15 in a one-gallon container.

But once you’ve decided the cost is worth the reward, you’ll find there are more than 300 different varieties from which to choose. Base your selection on the look you want in the leaves and the ultimate size of the tree that will best fit into your landscape.

Japanese maples offer varied and unique features including an interesting growth habit, fine leaf texture, and spring and fall leaf color. Their growth habit varies widely depending on the cultivar. Some are low and wide spreading, branching to the ground. Others are upright and vase-shaped. They may grow as single stemmed small trees or multi-stemmed shrubs. The trunks are gray and muscular-looking with horizontal branching that is layered, similar to flowering dogwoods. 

Leaf size, shape and color also differ among cultivars. Varieties are divided into groups based on how finely the leaves are dissected. Some varieties have red to purple-red foliage in the spring as the new leaves emerge, which change to green in the summer heat, turning red again in the fall. Others emerge green and remain so until fall, when they become a showy copper, orange, red or yellow. The leaves may be five to seven to nine lobed.

In addition to its pleasing appearance, the Japanese maple is also a very versatile plant. Cultivars of Japanese maple are adapted from zones 5 to 8. (The Augusta area is divided along zones 7b and 8a.) It can be used as a medium-size specimen tree, an accent plant, bonsai or even a border shrub depending on the type you select and the style of pruning. Mature heights range from about five or six feet to around 40 feet in the wild. But most fall in the 15- to 20-foot range. Plant low spreading, globose  varieties in areas with enough room to allow branches to droop to the ground. Be sure to clear all turf from beneath the branches of these low growing types so the tree will not be damaged by the lawn mower. Plant taller selections that can be “limbed up” next to patios or walkways.

Japanese maples can be a little finicky to grow unless they are planted in the right place, according to Fountain. “Plant them in the right soil, plant them at the right depth and keep them out of the sun after two in the afternoon,” he advises.

The ideal soil is evenly moist, slightly acidic, high in organic matter and well-drained. Native soil high in organic matter is hard to come by in the Augusta area, so it is recommended that you amend the soil. According to Fountain the right soil is a mixture of composted pine bark and rotted oak leaves. Since that is not something found naturally in every landscape, he recommends top dressing the root area with compost every spring.

Avoid areas with poor drainage. Japanese maples will grow in clay as long as the ground is sloped so water does not accumulate in the soil. Also if planting in clay, “Plant them up high, on top of the ground and bring the dirt to the plant,” says Fountain.

Plant in an area protected from high winds and late spring frosts since they tend to leaf out early. Direct sunlight can scorch leaves in the heat of the summer, so plant them in dappled shade, especially if irrigation is not provided.

One of Fountain’s secrets for growing beautiful Japanese maples is using the right fertilizer. He says one of the main things to remember is that maples shouldn’t get too much nitrogen.

This is a common problem since most people fertilize their trees with the same fertilizer they use on their lawns, which is usually really high in nitrogen. “Don’t put 10-10-10 or 16-4-8 granular fertilizer on them,” says Fountain. “Something like 5-10-15 is better, but use it at half strength. You can also use liquid Miracle Grow, but use that at half strength too. You just don’t want to burn them. Slow release granular like Osmocote is great, but again use it at about half strength,” he says.
Perhaps his best fertilizer secret is a product called Superthrive. Superthrive is actually not a fertilizer but a formula that contains more than 50 vitamins, hormones and other bio-usables for plants. It has been around for decades and nurseries and other professional growers swear by it. “I have been growing maples for about 12 years. Before I started using Superthrive I had some trees where the caliper just never would grow and get larger,” he says. “I started using Superthrive two years ago and I can tell you that not only have the calipers grown on these trees, but with all of my trees, I can tell they look better. The leaves look better, they have better color and the diameter of the tree at the top has gotten bigger.”

Water or the lack of it has a definite impact on maples. Our dry, hot summers, punctuated by periods of sometimes heavy rainfall, create a fluctuation of moisture that can cause dieback. “People need to understand that they are going to have some dieback on the maples as it is just something maples do,” says Fountain. “Part of it is because of our crazy weather. We can never depend on enough rain when we need it. But then when we do get rain, many times we get too much, so then they stay too wet. Then it’s the sun.  My best maples are on the north side of the house where they get very little sun.”

As a result, it’s important to provide your maples with irrigation for them to look their best. This can be accomplished with your regular sprinkler system or you can hand water them. Fountain suggests the perfect scenario would be drip irrigation. 

Japanese maples are susceptible to root problems, which is related to drought or overly wet conditions. They are also susceptible to a number of leaf spot diseases that can disfigure leaves and cause early defoliation.

Aphids and scale are the most common pests. Generally, though, a healthy tree is not plagued by pests. However, if you see signs of infestation, use labeled insecticides specifically for control of aphids and scale.

Nutrient deficiencies are not common in Japanese maples, but occasionally occur. Symptoms of deficiencies include yellow or yellowish-green leaves with darker green veins. The most common cause is lack of manganese. Even when your soil has adequate manganese the tree cannot absorb it if the pH is too high. A soil sample will help assure the proper pH for maximum manganese availability. If you find out lack of manganese is the issue, use one of the high-end fertilizers containing micro-nutrients.

Japanese maples usually need minimal pruning. Light pruning can be done, particularly when they are young, to develop tree size, shape and health. Infrequent and heavy pruning can devitalize the tree, resulting in a loss of food storage and feed generation capabilities. Sunscorch may also occur from heavy pruning, which in turn can lead to bark injury and cankers.

With the relatively high price of Japanese maples, some gardeners are tempted to cultivate them from seed. But according to Fountain they are difficult to grow from seed. And since they cross pollinate with others, there is no way of knowing what color tree you will end up with. 

If you already have a maple in your yard, you will often find that seedlings come up as volunteers. You can then dig them up and share them with a friend or replant them in another part of your landscape.